Amidoxime derivatives, useful as selective herbicide

ABSTRACT

The present invention relates to amidoxime derivatives of the formula (I): ##STR1## wherein R 1  is a C 1-3  alkyl or allyl group, a methyl group substituted by chlorine or fluorine atom or ethoxycarbonyl or diethyldithiophosphate group, a phenoxymethyl group unsubstituted or substituted by chlorine atom, a C 2  alkoxy or phenoxy group unsubstituted or substituted by chlorine atom or ethoxycarbonylethoxy group, a phenyl group unsubstituted or substituted by chlorine or fluorine atom, a benzyl group unsubstituted or substituted by chlorine atom, or a morpholine group; R 2  is a phenoxymethyl or phenoxyethyl group substituted by chlorine atom, a phenyl group substituted by chlorine atom or methoxy group, or an ethoxy group. The compounds of the invention have a extremely high selectivity between paddy rice or crop plants and weeds and a strong activity on weeds. Moreover, the compounds have a very low phytotoxicity to paddy rice and crop plants.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the new amidoxime derivatives having anexcellent herbicidal activity, method for preparation therefor and theherbicidal composition comprising it.

2. Description of the Invention

Phenoxy type herbicides such as 2,4-D, 2,4,5-T, MCPA and MCPB have beenemployed as post-emergence application to control paddy and uplandweeds. Since the phenoxy type herbicides cause the severe phytotoxicityto paddy rice and crop plants depending on the timing of application orthe weather conditions, it has been strongly desired to develop a newtype of herbicide which is able to overcome the phytotoxicity on paddyrice and crop plants and control annual and perennial weeds in paddy andupland field. In other words, a new type of herbicide should have aextremely high selectivity between paddy rice or crop plants and weedsand a strong activity on weeds.

SUMMARY OF THE INVENTION

Under the above circumstances, the present inventors conducted intensivestudies for developing herbicides having low phytotoxicity to paddy riceand crop plants and high selectivity between paddy rice or crop plantsand weeds. They found that amidoxime derivative of the followingformula(I) has low phytotoxicity, high selectivity and strong activity.

Accordingly, it is an object of the invention to provide a new type ofherbicide which can industrially be produced and which is able tocontrol annual and perennial weeds in paddy and upland field withkeeping high selectivity between crops and weeds.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to amidoxime derivatives of the formula(I)##STR2## wherein R₁ represents a C₁₋₃ alkyl or allyl group, a methylgroup substituted by chlorine or fluorine atom or ethoxycarbonyl ordiethyldithiophosphate group, a phenoxymethyl group unsubstituted orsubstituted by chlorine atom, a C₂ alkoxy or phenoxy group unsubstitutedor substituted by chlorine atom or ethoxycarbonylethoxy group, a phenylgroup unsubstituted or substituted by chlorine or fluorine atom, abenzyl group unsubstituted or substituted by chlorine atom, or amorpholine group; R₂ represents a phenoxymethyl or phenoxyethyl groupsubstituted by chlorine atom, a phenyl group substituted by chlorineatom or methoxy group, or an ethoxy group.

The compounds of formula(I) of this invention can be prepared, forexample, by the following process: ##STR3## wherein R₁ and R₂ have thesame meaning as defined above.

In other words, the compound(I) of this invention can be prepared byreacting the compound(II) with acylchloride of the compound(III).

The above reaction is carried out at room temperature in the presence ofa base for 1 to 5 hours. Various solvents can be used in this reaction,which include acetone, acetonitrile, toluene, ethylacetate, methylenechloride, ether, dioxane, etc. For the base, they may be employedtriethylamine, pyridine, sodium carbonate, potassium carbonate, etc.

After the reaction is completed, the objective products are separatedfrom the reaction mixture and purified according to a conventionalmethod. For instance, the reaction mixture is washed with water,followed by distillation of the solvent, and the residue being purifiedby chromatography to obtain a compound(I) at a high yield.

EXAMPLES

Now, the present invention will be described in further detail withreference to the following examples. However it should be understoodthat the present invention is by no means restricted to these specificexamples.

Example 1 O-(2,4-dichlorophenoxy)acetylchloroacetamidoxime: compound No.2

2.17 g of chloroacetamidoxime, 4.79 g of 2,4-dichlorophenoxyacetylchloride and 2.02 g of triethylamine were added to 50 ml of toluene. Themixture was stirred at room temperature for 1 hour. After completion ofthe reaction, the mixture was washed with 100 ml of water and thentoluene was distilled off, and the residue was purified by columnchromatography using a mixture of solvent (benzene:ether=4:1) to obtain5.92 g of the desired compound (yield: 95.1%).

Typical examples of the compounds obtained are shown in Table 1 withtheir physical properties.

    TABLE 1      ##STR4##          Element analysis (%)     Calculated value Compound  Physical     (Measured value) No. R.sub.1 R.sub.2 properties C H N NMR (δ,     ppm)           1 CH.sub.3 CH.sub.2      CH.sub.2     ##STR5##      mp 96-97° C. 47.23(47.31) 4.62(4.65) 9.18(9.23) 7.15-6.65(m,3H),     4.80(bs,2H), 4.75(s,2H), 2.05(t,2H), 1.53(m,2H), 0.91(t,3H)  2 FCH.sub.2      ##STR6##      mp 94-96° C. 40.69(40.57) 3.05(3.01) 9.49(9.56) 7.55-7.00(m,3H),     6.45(bs,2H), 5.05(s,2H), 4.92(d,2H)      3 ClCH.sub.2     ##STR7##      mp 92-93° C. 38.55(38.61) 2.91(2.96) 8.99(9.04) 7.30-6.80(m,3H),     6.20(bs,2H), 4.90(s,2H), 4.10(s,2H)      4 CH.sub.2CHCH.sub.2     ##STR8##      mp 99-100°      C. 47.55(47.62) 3.99(3.92) 9.24(9.32) 7.40-6.80(m,3H), 6.50- 6.01(m,1H),      5.90-5.70(m,2H), 5.60(bs,2H)4.85(s,2H), 3.10-2.90(m,2H)      5     ##STR9##      ##STR10##      mp 114-115°      C. 52.05(52.13) 3.82(3.78) 7.59(7.54) 7.40-6.80(m,8H), 6.40(bs,2H),     4.85(s,2H), 4.50(s,2H)      6     ##STR11##      ##STR12##      mp 86-87° C. 44.72(44.81) 4.04(4.11) 8.02(8.13) 7.20-6.60(m,3H),     5.45(bs,2H), 4.73(s,2H), 4.05(q,2H),3.17(s,2H), 1.22(t,3H)      7     ##STR13##      ##STR14##      mp 69-70° C. 36.45(36.51) 4.15(4.22) 6.07(6.14) 7.40-6.70(m,3H),     5.35(bs,2H), 4.80(s,2H), 4.40-4.05(m,4H),3.65(d,2H), 1.37(t,6H)  8      ##STR15##      ##STR16##      mp 167-168°      C. 50.73(50.81) 3.41(3.48) 7.89(7.93) 7.40-6.90(m,8H), 6.50(bs,2H),     4.80(s,2H)      9     ##STR17##      ##STR18##      mp 132-133°      C. 46.24(46.17) 2.85(2.92) 7.19(7.23) 7.40-6.80(m,7H), 6.50(bs,2H),     4.85(s,2H)  10 CH.sub.3 CH.sub.2      O     ##STR19##      mp 107-108°      C. 43.02(43.11) 3.94(3.89) 9.11(9.21) 7.30-6.70(m,3H), 4.70(s,2H),     4.70-4.30(bs,2H), 4.10(q,2H),1.35(t,3H)      11     ##STR20##      ##STR21##      mp 117-118°      C. 50.97(50.80) 4.28(4.22) 5.94(6.02) 7.51-6.73(m,7H), 6.25(bs,2H),     5.02-4.62(m,3H), 4.18(q,2H),1.51(d,3H), 1.18(t,3H)  12 Cl.sub.3 C      ##STR22##      mp 109-111°      C. 31.56(31.47) 1.84(1.80) 7.36(7.47) 7.65-7.00(m,3H), 5.95(bs,2H),     4.85(s,2H)  13 CH.sub.3 CH.sub.2      CH.sub.2     ##STR23##      oil 47.23(47.12) 4.62(4.58) 9.18(9.27) 7.29-6.87(m,2H), 5.11(bs,2H),     3.78(s,3H), 2.21(t,2H)1.62(m,2H), 0.97(t,3H)  14 C.sub.2 H.sub.5     OCH.sub.2      CH.sub.2     ##STR24##      mp 90-91° C. 46.58(46.67) 4.81(4.78) 8.36(8.39) 7.30-6.84(m,2H),     5.30(bs,2H), 3.76(s,3H), 3.64-3.20(m,4H),2.39(t,2H), 1.05(t,3H)  15      ##STR25##      ##STR26##      mp 122-123°      C. 45.52(45.44) 2.87(2.89) 6.64(6.58) 7.30-6.89(m,5H), 4.96(bs,2H),     3.76(s,3H), 3.54(s,2H)      16 CH.sub.3     ##STR27##      oil 43.34(43.17) 3.64(3.59) 10.11 (10.22) 7.30-6.91(m,2H), 5.21(bs,2H),     3.76(s,3H), 1.90(s,3H)      17     ##STR28##      ##STR29##      mp 113-114°      C. 43.86(43.72) 2.76(2.74) 6.40(6.45) 7.31-6.84(m,5H), 5.08(bs,2H),     4.70(s,2H), 3.76(s,3H)      18     ##STR30##      ##STR31##      mp 150-151°      C. 44.15(44.22) 2.47(2.46) 6.87(6.82) 7.31-6.80(m,5H), 5.17(bs,2H),     3.76(s,3H)      19     ##STR32##      ##STR33##      mp 143-144° C.  48.02(48.13) 2.69(2.74) 7.47(7.42) 7.42(m,5H),     5.21(bs,2H) 3.76(s,3H)      20     ##STR34##      ##STR35##      mp 115-116°      C. 44.84(44.76) 4.34(4.30) 12.07(12.14) 7.30-6.91(m,2H), 4.99(bs,2H),     3.80-3.61(m,7H), 2.99-2.80(m,4H)      21     ##STR36##      ##STR37##      mp 142-144°      C. 61.35(61.22) 5.15(5.23) 8.42(8.55) 7.60-7.20(m,9H), 5.80(bs,2H),     4.60-4.20(q,1H), 3.45(s,2H),1.80-1.60(d,3H)      22     ##STR38##      ##STR39##      mp 134-135°      C. 60.29(60.38) 4.74(4.82) 8.79(8.62) 7.50-7.20(m,9H), 5.80(bs,2H),     4.60-4.30(q,1H), 1.90-1.70(d,3H)      23     ##STR40##      ##STR41##      mp 147-148°      C. 54.41(54.37) 3.99(4.07) 7.93(7.98) 7.60-7.10(m,8H), 5.90(bs,2H),     4.60-4.20(q,1H), 1.80-1.60(d,3H)      24     ##STR42##      OCH.sub.2 CH.sub.3 mp 122-124° C. 43.02(43.07) 3.94(3.89)     9.12(9.07) 7.25-7.01(m,3H), 6.30(bs,2H), 4.50(s,2H), 4.40-4.02(q,2H),1.50     -1.15(t,3H)

The compounds of the present invention may be used as they are butnormally they are used in the form of such as wettable powders, dusts,emulsion concentrates, suspension concentrates, or may be used afterdilution with water.

When liquid formulations are applied, the solvent such as water,alcohol, ether, acetone, ester, amide or petroleum ether may be used. Asthe solid carrier, an inorganic powder such as magnesium lime, gypsum,calcium carbonate, silica, alumina, zeolite, clay mineral and resinpowder may be used.

The dosage of the present invention to be used as an active ingredientmay be varied depending on the type of formulation, the manner forapplication, the timing and the weather condition. The dosage is usuallyvaried in a range of 0.25 to 4 Kg/ha.

The compounds of the present invention are sufficiently effective evenif they are applied solely. However, their application in combinationwith one or more types of compounds having herbicidal activity makes apossibility not only reduce the amount of the active ingredient, butalso attain the enlargement of the herbicidal spectrum or improve theeffects.

The typical examples of herbicides that can be used together with thecompounds of the present invention are mentioned, for example, amide -type herbicides such as monalide, propanil, solan, diphenamide,fluoridamide, mefluidine, benzamizole, butachlor and alachlor;dinitroaniline - type herbicides such as trifluralin, benfluralin,profluralin, isopropaline, pendimenthalin and ethalfluralin; urea - typeherbicides such as buturon, monolinuron, parafluron, tetrafluron,linuron, sulfodiazol, buthiuron, chlorosulfuron and sulfomethuronmethyl;carbamate - type herbicides such as chlorobufam, barban, diallate,phenmedipham, butylate, triallate, bentiocarb and methylbencarb;diphenylether - type herbicides such as oxyfluorofen, acifluorfornethyl,lactofen, formesafen and fluoronitrofen; and diazine - type herbicidessuch as oxadiazon and immazaquim.

Formulation Examples

Some examples of the formulations are given below.

Formulation Example 1 (Emulsion concentrate)

30 parts of compound No. 2 of the present invention, 60 parts ofm-xylene and 10 parts of surfactant mixture(polyoxyethylene alkyl arylether and sodium alkyl aryl sulfate) were uniformly mixed and stirred toobtain an emulsion concentrate.

Formulation Example 2 (Wettable powder)

10 parts of compound No. 10 of the present invention, 85 parts of whitecarbon and 5 parts of surfactant mixture(polyoxyethylene alkyl arylether sulfate and polyoxyethylene alkyl and aryl ether) were mixed andpulverized to obtain a wettable powder.

Formulation Example 3. (Granule)

3 parts of compound No. 4 of the present invention, 60.0 parts ofbentonite, 35 parts of talc, 0.5 parts of sodium dodecyl benzenesulfonate, 0.5 parts of sodium metasilicate and 1.5 parts of sodiumtripolyphosphate were mixed, and after an addition of a proper amount ofwater, kneaded. The mixture was granulated by using an extrusiongranulating machine and dried by a conventional method to obtaingranules.

TEST EXAMPLES Test example 1

Herbicidal test against paddy field weeds.

Paddy field soil was filled in 140 cm² plastic pot and irrigated. Paddyrice seedlings (Variety: Dongjin) of 2.5 leaf stage were transplantedand some amounts of paddy field weeds were also sown. On the second dayafter the transplantation, a predetermined amounts of the compound ofthe present invention was applied in the form of wettable powder.

During the test period, 2 cm in height of water from the surface of soilin the pot was maintained. Upon twentieth day after the treatment withcompound of the present invention, the herbicidal effects against theweeds and phytotoxicity against paddy rice plants were examined. Theresults are shown in table 2 and herbicide rating system is shown intable 4.

                                      TABLE 2                                     __________________________________________________________________________    4 kg/ha                                                                       Compound                                                                      NO.   ORYSA                                                                              ECHOR                                                                              SCPJU                                                                             BR.s                                                                             ANEKE                                                                              MOOVA                                                                              CYPDI                                                                              CYPSE                                                                              SAGPY                              __________________________________________________________________________     1    50    95         100  100  100                                           2    30   100  100 100               100  100                                 3    40   100  100    100   90  100                                           4    40   100  100    100  100  100                                           5    60   100  100    100  100  100                                           6    40    90  100    100  100  100                                           7    60   100  100    100  100  100                                           8    80   100  100    100  100  100                                           9    50   100         100  100  100                                          10    80   100  100    100  100  100                                          11    60   100   80  90                80  100                                12    60    80   90 100                50  100                                13    70   100   90 100               100  80                                 14    70   100  100 100               100  20                                 15    70   100   90 100               100  50                                 16    80   100  100 100               100  90                                 17    80   100  100 100               100  90                                 18    80   100  100 100               100  90                                 19    80   100  100 100               100  90                                 20    80   100  100 100               100  90                                 21    50    60         100  100  100                                          22    40    60         100   90   80                                          23    50    60          90   90   80                                          24    70   100  100    100  100  100                                          __________________________________________________________________________     *BR.s: mixture of annual broad leaf weeds such as ANEKE (dayflower), MOOV     (monochoria), ROTIN (toothcup) etc.                                      

    ______________________________________                                        PADDY WEED SPECIES                                                                                        ENGLISH                                           ABRV.  GENUS-SPECIES NAME   NAME                                              ______________________________________                                        ORYSA  Oryza sativa L.      Rice                                              ECHOR  Echinochloa curs-galli                                                                             Barnyardgrass                                            P. BEAUV. var. oryzicola OHWI                                          SCPJU  Scirpus juncoides ROXB.                                                                            Bulrush                                           CYPDI  Cyperus difformis L. Umbrellaplant                                     CYPSE  Cyperus serotinus ROTTB.                                                                           Flat-sedge                                        ANEKE  Aneilema keisak HASSK.                                                                             Dayflower                                         MOOVA  Monochoria vaginalis PRESL.                                                                        Monochoria                                        ROTIN  Rotala indica KOEHE. Toothcup                                          SAGPY  Sagittaria pygmaea MIQ.                                                                            Arrow head                                        ______________________________________                                    

Test Example 2

Herbicidal test against upland weeds.

Alluvial soil was filled in 350 cm² plastic pot. Seeds of 10 weedspecies and seeds of corn, wheat, soybean, tomato and orchardgrass weresown and covered with soil. The pot was kept in a greenhouse. A testcompound was formulated into an emulsion concentrate and diluted withwater. A determined amounts of the compounds of the present inventionwas sprayed on the soil or over the leaves and stems of the plants bymeans of a small size spraying machine. The herbicidal effects againstthe weeds and the phytotoxicity of the crop plants were evaluated uponexpiration of 2 to 3 weeks from the application. The results are shownTable 3 and herbicide rating system is shown in Table 4.

                                      TABLE 3                                     __________________________________________________________________________    PRE-Emergence 0.5 kg/ha                                                       __________________________________________________________________________    Compound                                                                            UPLAND WEED SPECIES                                                     NO.   LYPES                                                                              TRZAW                                                                              GLXMX                                                                              ZEAMX                                                                              DACGL                                                                              AMAVI                                                                              DIGSA                                                                              RUMJA                                                                              POLHY AESIN                                                                              CAGHE                __________________________________________________________________________     1    90   40   90   20   70   100  100  60   40    60   100                   2    100  60   70   60   90   100  100  90   80    100  100                   3    100  55   65   55   90   100  100  90   75    100  100                   4    90   20   70   30   70   100  100  80   60    80   100                   5    90   50   60   40   80   100   80  40   30    40   100                   6    80   45   60   20   70   100   90  40   60    60   100                   7    50   30   65   20   60    95   60  30   30    50   100                   8    75   10   65   40   70   100   90  30   55    40   100                   9    50   20   60   40   50   100   80  10   60    80   100                  10    90   40   70   40   40   100   95  40   50    80   100                  11    90   20   60   10   40   100   80  10   10     0    0                   12    90   50   80   20   80   100  100  80   80    90   100                  13    100  95   100  60   80   100  100  100  100   100  100                  14    100  100  100  70   100  100  100  100  100   100  100                  15    100  100  100  70   90   100  100  100  100   100  100                  16    100  90   100  60   80   100  100  100  100   100  100                  17    100  80   100  60   70   100  100  90   100   100  100                  18    100  80   100  60   70   100   80  100  100   100  100                  19    100  80   100  60   100  100  100  90   100   100  100                  20    100  80   100  60   90   100  100  100  100   100  100                  21    100  50   65   50    0    70   70  80   80    70    80                  22    60   30   30    0    0    65   70  65   70    80    85                  23    20    0    0    0   30    70   65  70   75    85    40                  24    30    0   40   30   50   100   95  10    0    20   100                  __________________________________________________________________________                                         Compound                                                                            PADDY WEED SPECIES                                                      No.   ORYSA                                                                              ECHOR                                                                              CYPDI                                                                              ANEKE               __________________________________________________________________________                                          1    100  70   100  100                                                       2    100  90   100  100                                                       3    100  85   100  100                                                       4    100  95   100  100                                                       5    100  95   90   100                                                       6    100  90   85   100                                                       7    100  95   60   100                                                       8    95   75   80   100                                                       9    100  75   80   100                                                      10    100  70   90   100                                                      11    90   70   70    80                                                      12    90   20   20   100                                                      13    80   30   90   100                                                      14    100  40   50    90                                                      15    90    0   70    50                                                      16    90   80   100  100                                                      17    90   80   100  100                                                      18    80   70   100  100                                                      19    90   90   100  100                                                      20    90   80   100  100                                                      21    70   65   80   100                                                      22    45   60   60    85                                                      23    40   60   30    75                                                      24    10   20   30    60                 __________________________________________________________________________

    ______________________________________                                        TEST PLANT FOR HERBICIDE EVALUATION                                                                         ENGLISH                                         ABRV.  GENUS-SPECIES NAME     NAME                                            ______________________________________                                        UPLAND SPECIES                                                                LYPES  Lycopersicon esculentum MILL.                                                                        Tomato                                          TRZAW  Triticum aestivum L.   Wheat                                           GLXMX  Glycine max (L.) MERR. Soybean                                         ZEAMX  Zea mays L.            Corn                                            DACGL  Dactylis glomerata L.  Orchard                                                                       grass                                           AMAVI  Amaranthus viridis L.  Pigweed                                         DIGSA  Digitaria sanguinalis (L.) SCOP.                                                                     Large                                                                         crabgrass                                       RUMJA  Rumex japonicus HOUTT. Dock                                            AESIN  Aeschynomene indica L. Indian                                                                        jointvetch                                      CAGHE  Calystegia japonica CHOISY                                                                           Bindweed                                        POLHY  Polygonum hydropiper L.                                                                              Smartweed                                       COMCO  Commelina communis L.  Common                                                                        dayflower                                       PADDY SPECIES                                                                 ORYSA  Oryza sativa L.        Rice                                            ECHOR  Echinochloa crus-galli P.BEAUV. var.                                                                 Barnyard-                                              oryzicola OHWI         grass                                           CYPDI  Cyperus difformis L.   Umbrella-                                                                     plant                                           ANEKE  Aneilema keisak HASSK. Dayflower                                       ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Herbicide Rating System                                                       Rating Description                                                            Percent                                                                              of Main   Crop          Weed                                           Control                                                                              categories                                                                              Description   Description                                    ______________________________________                                         0     No effect No crop reduction                                                                           No weed control                                                 or injury                                                    10               Slight discoloration                                                                        Very poor weed                                                  or stunting   control                                        20     Slight    Some discoloration,                                                                         Poor weed control                                     effect    stunting or stand                                                             loss                                                         30               Crop injury more                                                                            Poor to deficient                                               pronounced but not                                                                          weed control                                                    lasting                                                      40               Moderate injury,                                                                            Deficient weed                                                  crop usually  control                                                         recovers                                                     50     Moderate  Crop injury more                                                                            Deficient to                                          effect    lasting, recovery                                                                           moderate weed                                                                 control                                        60               Lasting crop inury                                                                          Moderate weed                                                   no recovery   control                                        70               Heavy injury and                                                                            Control somewhat                                                stand loss    less than satisfactory                         80     Severe    Crop nearly   Satisfactory to good                                  effect    destroyed a few                                                                             weed control                                                    survivors                                                    90               Only occasional live                                                                        Very good to                                                    plants left   excellent control                              100    Complete  Complete crop Complete weed                                         effect    destruction   destruction                                    ______________________________________                                    

What is claimed is:
 1. An amidoxime derivative of the formula(I)##STR43## wherein R₁ represents fluromethyl, trichloromethyl,ethoxycarbonylmethyl, diethoxythiophosphonylthiomethyl,phenoxymethylethoxyethyl, allyl, phenoxy, chlorophenoxy, ethoxy,ethoxycarbonylethoxyphenoxy, benzyl, dichlorobenzyl, difluorophenyl,dichlorophenyl and morpholinyl group; and R₂ representsdichlorophenoxymethyl, chlorophenoxyethyl, ethoxy andmethoxydichlorophenyl group.
 2. A method for controlling annual andperennial weeds in a rice paddy, comprising the application to said ricepaddy of an herbicidally effective amount of one or more of a compoundof formula(I) as defined in claim
 1. 3. An herbicidal compositioncomprising as an active ingredient one or more of a compound offormula(I) as defined in claim 1 and an inert carrier or diluent.